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Evaluation of the Inhibitory Gel Aloe vera against Corrosion of Reinforcement Concrete in NaCl Medium

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Materials Sciences and Applications 2024年第5期15卷 101-112页

作者： malang bodian Dame Keinde Kinda Hannawi Modou Fall Aveline Darquennes Prince William Agbodjan Laboratoire de Chimie Physique Organique et d’ Analyse Environnementales (LCPOAE) D&#233partement de Chimie Universit&#233 Cheikh Anta Diop de Dakar Dakar Senegal Laboratoire de Gé nie Civil et G&#233nie M&#233canique (LGCGM) INSA Rennes Universit&#233 de Rennes Rennes France Civil Engineering Materials Laboratory (LMGC) Ecole Sup&#233rieure Polytechnique de Dakar (Senegal) Universit&#233 Cheikh Anta Diop Dakar S&#233n&#233gal

Most reinforced concrete structures in seaside locations suffer from corrosion damage to the reinforcement, limiting their durability and necessitating costly repairs. To improve their performance and durability, we have investigated in this paper Aloe vera extracts as a green corrosion inhibitor for reinforcing steel in NaCl environments. Using electrochemical methods (zero-intensity chronopotentiometry, Tafel lines and electrochemical impedance spectroscopy), this experimental work investigated the effect of these Aloe vera (AV) extracts on corrosion inhibition of concrete reinforcing bar (HA, diameter 12mm) immersed in a 0.5M NaCl solution. The results show that Aloe vera extracts have an average corrosion-inhibiting efficacy of around 86% at an optimum concentration of 20%.

关键词： Reinforced Concrete Green Inhibitor Corrosion Reinforcement Electrochemical Methods

Experimental Study of the Anti-Corrosion Performance of Montmorillonite K-10 on Rebar in HCl Environment: Application in Mortar for the Rehabilitation of Reinforced Concrete Degraded by Corrosion

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Open Journal of Civil Engineering 2024年第2期14卷 155-167页

作者： malang bodian Mariétou Barro Diop-Fall Dame Keinde El-Hadji Dieye Modou Gningue Diop Modou Fall Laboratoire de Chimie Physique Organique et dAnalyse Environnementales (LCPOAE) Dpartement de Chimie Univ Cheikh Anta Diop de Dakar Dakar Senegal Laboratoire de Matriaux de Gnie Civil (LMGC) Ecole Suprieure Polytechnique de Dakar Univ Cheikh Anta Diop Dakar Sngal

This work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. The corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. This is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. The aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. The results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.

关键词： Clay Reinforced Concrete Corrosion Inhibitor Rehabilitation Electrochemical Methods

Evaluation of the Inhibitory Gel Aloe vera against Corrosion of Reinforcement Concrete in NaCl Medium

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Electrochemical Study of the Corrosion Inhibitory Capacity of Calcined Attapulgite in Reinforced Concrete Medium

Materials Sciences and Applications（材料科学与应用期刊） 2024年第5期 101页

作者： malang bodian Dame Keinde Kinda Hannawi Modou Fall Aveline Darquennes Prince William Agbodjan

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Comparative Evaluation of the Chemical Composition and Physical Properties of Reinforced Concrete Steel Bars Used in Construction in Senegal

Advances in Materials Physics and Chemistry（材料物理与化学进展） 2024年第5期 76页

作者： malang bodian Kinda Hannawi Dame Keinde Modou Fall Aveline Darquennes Prince William Agbodjan

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Open Journal of Civil Engineering 2023年第2期13卷 292-302页

作者： El Hadji Amadou Fall Sy Dame Keinde malang bodian Laboratory for Water Energy Environment and Industrial Processes (LE3PI) Higher Polytechnic School Cheikh Anta Diop University Dakar Senegal Laboratory of Civil Engineering Materials (LMGC) Higher Polytechnic School Cheikh Anta Diop University Dakar Senegal

This article presents, the study of a comparative evaluation of the chemical composition and physical properties, linear mass deviations, of four (04) types of steel used in the construction sector in Senegal. Type 1 (E1), Type 2 (E2) and Type 3 (E3) steels are produced by locally established companies and Type 4 (E4) witness bars are imported from the France. The chemical analyses of the different types of steel were carried out by combustion, infrared (IR) detection for carbon and sulfur, by reducing fusion for nitrogen and by optical emission spectrometer (SEO) for the rest of the elements. The composition was determined on bars with a diameter of 10 mm. Linear mass deviations were evaluated for steels with a diameter of 8 mm, 10 mm and 12 mm. The results of the chemical analyses showed that the limit value for the percentage of carbon was exceeded by 29.16% for the steel, type 3. For the other types (1, 2 and 4), the limit values set out in the French standard NF EN 10,080 are not exceeded. As regards the relative differences in mass, the results showed that for steels of local manufacture, all the samples of bars with diameters 10 and 12 mm and 33% of steels with diameters 8 mm do not comply with the standard. The results also indicate that the chemical composition and relative linear mass deviations of the steels, type 4 comply with the standard. Thus, locally manufactured steels are not always suitable for use in reinforced concrete constructions.

关键词： Local Manufacturing Reinforced Concrete Durability Eurocode 2

Study of Attapulgite as an Additive in Reinforced Concrete by Substitution of Cement and Its Effects on the Durability Properties of Hardened Concrete

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Open Journal of Civil Engineering 2022年第3期12卷 301-319页

作者： malang bodian Dame Keinde Ismaila Yade Kinda Hannawi Prince William Agbodjan Modou Fall Aveline Darquennes Organic Physical Chemistry and Environmental Analysis Laboratory (LCPOAE) Chemistry Department Cheikh Anta Diop University Dakar Senegal Laboratoire de Génie Civil et Génie Mécanique (LGCGM) Université de Rennes INSA Rennes Rennes France Civil Engineering Materials Laboratory (LMGC) Higher Plytechnic School Cheikh Anta Diop University Dakar Senegal

The valorization of Senegalese attapulgite clay in concrete, as a solution against the exhaustion of the cement deposits was studied. In that purpose, attapulgite was first calcined at 800°C to make it reactive and added in concrete by substitution of Portland cement (CEM I 52.5N) at contents of 0, 5 and 10% by conserving a constant water/cement ratio value of 0.65. The effects of the partial replacement of cement by attapulgite on the physicochemical and mechanical properties of the concrete as well as on the steel-concrete bond were examined. For this purpose, the water porosity, the intrinsic permeability and the density of the clay-based concrete were evaluated. Compression, tensile and pull-out tests were carried out to determine the impact of clay on the Young modulus, the compressive and tensile strengths and the steel-concrete bond. This study was completed by a characterization of the pozzolanic reactivity of calcined attapulgite. All the results of these studies were compared with those of Portland cement as a reference. The substitution of cement by attapulgite up to 10% in concrete has only a small influence on its porosity and permeability and confers to the concrete gain in compressive strength of 11%. However, it caused a loss of steel-concrete bond of 10%.

关键词： Attapulgite Concrete Mechanical Properties Pozzolanic Reactivity Rein-forced Concrete

Totally Occluded Coarctation of the Aorta in a Young Adult

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World Journal of Cardiovascular Diseases 2024年第4期14卷 282-287页

作者： Marguerite Téning Diouf Mohamed Leye Joseph Salvator Mingou Aw Fatou Ndeye Faye Sy Aimé Mbaye Malick bodian Aliou Alassane Ngaidé Abdoul Kane Cardiology Dalal Jamm Hospital Dakar Senegal Training and Research in Health Sciences Unit University of Thi&#232s Thi&#232s Senegal Cardiology Department Hospital Aristide Le Dantec Dakar Senegal

We report the case of a 20-year-old female patient presenting with a totally occluded coarctation of the aorta. The patient was admitted for the evaluation of resistant grade III high blood pressure. The physical examination revealed a blood pressure gradient between the upper and lower limbs, absent femoral pulses, a diffuse continuous murmur over the chest, and hyperpulsatility of the carotid arteries and sternal notch. A transthoracic echocardiography outlined a narrowing in the caliber of the isthmic aorta without acceleration of flow or gradient. Thoracic CT angiography revealed a complete aortic coarctation with interruption of continuity between segment 3 and the descending aorta.

关键词： Coarctation of Aorta Complete Aortic Occlusion High Blood Pressure Adult

Thrombolysis in Pulmonary Embolia at the Cardiology Department of Aristide le Dantec Cardiology Department

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World Journal of Cardiovascular Diseases 2024年第9期14卷 521-538页

作者： Joseph Salvador Mingou Marguerite Téning Diouf Fatou Aw Simon Antoine Sarr Khadim Rassoul Diop Malick bodian Mouhamadou Bamba Ndiaye Maboury Diao Abdoul Kane Cardiology Department Aristide le Dantec Hospital Dakar Senegal Cardiology Department Dalal Jam Hospital Dakar Senegal

Introduction: Venous thromboembolic disease is the 3rd most common cardiovascular pathology. Acute pulmonary embolism constitutes its most serious presentation and a major cause of mortality, morbidity and hospitalization in Africa and Senegal. The objectives of this work were to study the epidemiological profile of pulmonary embolisms and to evaluate the practice of thrombolysis in patients in a cardiological setting. Methodology: A retrospective, descriptive study was carried out in the Cardiology department of the Aristide le Dantec Hospital (HALD) over the period from August 2011 to December 2019 in patients hospitalized in the cardiology department for pulmonary embolism confirmed by CT angiography and/or with thrombi on cardiac ultrasound and who had also benefited from thrombolysis. Results: Thirty-one patients with pulmonary embolism were thrombolyzed. There was a predominance of the female gender with an average age of 45.97 years. Risk factors were dominated by age (61.29%) followed by obesity (32.26%) and prolonged immobilization (22.5%). The functional signs were dominated by dyspnea (77.42%) followed by chest pain (51.62%) and cough (35.48%). The physical signs were dominated by right heart failure in 22.5% of cases, pulmonary condensation syndrome in 19.35%, and inflammatory large leg in 12.9% of cases. Echocardiography and chest CT angiography were the means of diagnosis. Nine of our patients presented with an intracardiac mass. Thrombotic treatment was administered in all patients. The average length of hospitalization was 12.32 days and in-hospital mortality was 32.26%. Conclusion: Pulmonary embolism does exist in our regions and is responsible for heavy mortality. Rapid and efficient support is essential. Prevention remains the corner-stone in the fight against this pathology.

关键词： Pulmonary Embolism Thrombolysis Senegal

Effects of Chemical Treatment on the Physical Properties of Typha

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Fluid Dynamics & Materials Processing 2022年第5期18卷 1409-1418页

作者： Ibrahima Diaw Mactar Faye Seckou bodian Vincent Sambou Efficiency and Energetic Systems Research Group Alioune Diop UniversityBambeyBP 30Senegal Laboratoire Eau EnergieEnvironnement et Procédés Industriels(LE3PI)Cheikh Anta Diop UniversityDakar-FannBP 5085Senegal

Plant-based concretes are produced from plant aggregates and a *** fibers are mainly composed of saccharides(sugars)and these sugars can decrease the concentration of Ca2+ions in the cement pore solution and delay the formation of hydration *** improve the interfacial bond between fibers and matrix a chemical treatment is widely *** study investigates the effect of sodium hydroxide treatment on physical and hygroscopic properties of Typha *** particular,a 5%sodium hydroxide solution is used to treat these aggregates and their bulk and absolute densities,porosity,water content and water absorption are evaluated *** indicate that bulk and absolute densities increase after treatment from 56.44 kg/m^(3) to 122.57 kg/m^(3) and 541.93 kg/m^(3) to 555.17 kg/m^(3),*** treatment reduces porosity of Typha from 89.58%to 77.92%and decreases water content from 1.4%to 1%.The treatment with sodium hydroxide reduces substantially the water absorption of the aggregates.

关键词： Sodium hydroxide treatment typha aggregates hygroscopic properties physical properties